Started the car up this morning to go to work, after a minute or so, I heard a loud pop and steam hissing. Turned car off straight away, but I am dead worried something is really wrong with the car now 
It needed a top up of anti freeze over xmas, which the other half bought, but since told me this morning, he never actually put in
Is this going to be an expensive problem?
Got a lift into work, so the car is still sat outside with nowhere else to put it 

It needed a top up of anti freeze over xmas, which the other half bought, but since told me this morning, he never actually put in

Is this going to be an expensive problem?

